Hydraulic control valve



Oct. 14, 1952 H. c. WEIMAR 2,613,906

HYDRAULIC CONTROL VALVE Filed May 25, 1948 2 SHEETS-SHEET 1 72 w '1 4 5;g 3 2% A; 7% #8, #6 n1 /6/% I 26 a Oct. 14, 1952 H. c. WEIMAR 2,613,906

HYDRAULIC CONTROL VALVE Filed May 25, 1948 2 SHEETSSHEET 2 5 4 .16 R 1651 I 1 :1 J

L J Lvl 17 J7: .16 .19 1 9490 2 52 fig? Patented Oct. 14, 1952 HYDRAULICCONTROL VALVE Hans C. 'Weimar, Providence, R. L, assig'nor to Brown andSharpe Manufacturing Company, Providence lt. I., a corporation of RhodeIsland Application May 25, 1948, Serial No. 29,042

8 Claims.

The present invention relates to an improved hydraulic control valve,and is herein disclosed in a preferred. form .as embodied in a peedcon.- trol valve adapted for controlling the rate of movement of amachine tool support as, for example, a hydraulically actuated grindingmachine wor'ksupporting table.

It is a principal object of the invention to pro vide a novel andimproved control valve" of which theimovable'valve element is adaptedfor adjustment by substantially evenly spaced increments of movementover" a reasonable range from a closed toa fully opened position, and ofwhich the throttle opening is arranged to be adjusted by said incrementsof movement from a closed to a fully opened position to provide a seriesof accurately determined very slow speeds of the driven support whichmay range, for example,

from one to several inches per minute, and thereafter a series of morewidely spaced higher speeds as the valve element approaches its fullyopened position,

It is a further object of the invention to providea novel and. improvedcontrol'valve of which the throttle opening is increased proportionatelyas the square of the distance moved by the'movablevalve element, whichis simple and economical in construction, and adapted for easy manualadjustment for the: accurate control of. the rate of support movement.

lit is a further object of the invention to provide": asimple andeiiicient valve construction includlng means available ininitiallyadjusting the valve mechanism to accurately ascertain the startingposition of the valve and to provide accurate calibration of. the valveparticularly over the very slow speed range in accordance with asimpleand effective method of adjustment hereinafter more fully set forth. 7

With the above: and other objects" in view as may hereinafter appear, aprincipal feature of the inventloneonsists in the provision orcylindrical valveand. sleeve elements which are inscrewthreaded.relation to one another so that a com.- bined rotational and axialmovement of one element relative to the other is effected, and which areformed. with rectilinear apertures arranged to be moved diagonally intooverlying: relation.

v 2 a a p in the sleeve element is formed by means of a transverse outof a depth extending nearly to: the axis of the sleeve and of a widthpreferably greater than required for full valve opening. The

cooperating rectangular opening in the valve member is formed byslabbing off half the diameter of the valve member at its inner end. The5 efiective opening or aperture oftheyvalve in any position isdetermined by the amount of overlap of the semi-cylindrical edge of theslabbed-ofi portion of the valve member and a transverse edge of theslot in the sleeve member in one direction and the amount of overlap oftwo cooperating side edges of the respective valve and sleeve elementsin the other direction. l

Another feature of the invention consists in the novel construction andarrangementof, the

valve assembly to facilitate an'jinitial accurate adjustment of thevalvemechanism including a rotatably adjustable nut into' which the valvestem is threaded for imparting-the desired r o,-'

tational andaxial movements to the valve memberto open and close thevalve, In the illus-v trated construction, the nut element is circularin form, and is angularly adjustable by means of v asuitable pin wrench,being normally secured in adjusted position by means. of anoverlyingaxial movement of thevalve element, and the manuallyxoperable controlknob; 2 :is.

end-view of the control knob and its associated. dial shown. in Fig. 1looking from the-left; is a view similar to Fig. 2, but with the controlknob removed. and portions of the underlying adjustable nut andassociated clamp ring broken away'and' sectioned; Fig"; 4 is a sectionalview taken 'onfthe line 44 of Fig. 1, showing the valve in its fullyopen position; Fig.- l5is a view similarto Fig; 4: showing the valvethrottle and more particularly the side ports in intermediate orhalf-way position between fully opened'zandv shut-off position; Fig. disa view similar to "accordance with the parabolic law.- The-controlvalveillustrated in the drawings ias embodying in a preferred form theseveral 3 Figs. 4 and 5, but with the valve shown in its fully closedposition; Fig. 7 is a fragmentary developed view showing the relation ofthe valve stem and cylinder with the valve fully opened as shown in Fig.i; Fig. 8- is a developed view similar to Fig. 5, in which the valvestem has been turned half-way to its shut-off position; Fig. 9 is adeveloped View of the parts in the shut-off position shown specificallyin Fig. 6; Fig. 10 is a view of the valve control mechanism looking fromthe left, but with the manually operable knob removed and a pair ofgauging devicesapplied respectively. to the valve stem and rotatablyadjustable nut preparatory for adjustment; Fig. ll is a sectional viewlooking 'fromthe right,

taken on the line H-ll of Fig. 10; Figs. 12 to V s 16 inclusive, are aseries of developed diagram-a matic view showing successive positions ofthe relatively movable valve elements in positions taken during theprocess of adjusting the degreater than is required for the maximumthrottle opening of the valve. A'cooperating port opening is formed inthe inner right hand end of the valve member 12 in the form of asemi-cylindrical cutout in the end of the valve member. With the valvein the fully opened position shown, for example, in Fig. 1, liquid underpressure is admitted through the, inlet pipe 24 to the port 28, throughthe port 39' in the valve member, and thence outwardly to the right byway of the end of the valve sleeve Hi to the outlet pipe 26.

The valve member I2 is arranged to have imparted thereto a combinedrotational and axial movement which has the effect of causing therectangularly-shaped apertures provided by ports 28 and 30 to movediagonally into overlying relation attheir adjacent corners to open sothat the vice; Figs. 17 to 21 inclusive, correspond respectively'withthe positions of the valve elements shown'in Figs. 12 to 16; and Fig. 22is a diagram illustr'atingthe manner in which the throttle opening ofthe valve and related rate of drive of thehydraulically driven support iincreased in =feature's'g'of the invention, is particularly adapted and:is calibrated to control the rate of movement of: -ahydraulically-actuated grinding machine worksupportin'g table having-arange of operat- 'ing speeds fromgone inch per minute up to any desiredmaximum, which may for example be the ldl inches per minute indicated onthe dial of Fig. '2. -In--actual operation, a close control of the'rateof'travel of the table is desirable at the lo'wer'spe'eds,-.while at thesame time provision m'ust also'be made for a reasonable range ofoperating table speeds at much'higher feed rates. *Adifference ofspeed-amounting to an inch'per 'minute within theslow speed rangeextending from one to six inches of travel of the grinding machine tablemay be of considerable-conselqu'ence, for-example, in connection withwheel :truin'gl In carrying out the present invention, a simple and yeteiiicient valve mechanism ha been developed, inwhi'ch themovable valveelement'is arranged to be shifted through approximately equalincrementsofdistance to successive'posi "tions of adjustment in order toprovidefora .sure is introduced intov the valve assembly by mean of aninlet duct. 24, ,passes' through a throttle'opening inthe,valve,-and isthen dis charged-through an .outlet 26 connecting with theouter'end ofthevalve sleeve'member Hl. Cooperatingports are formed in thevalvesleeve member l4 and valve member 12 which are rendered operative by. acombined rotational and axial movement of the-valve member I2. tocontrol the amount of fluid passing through the valve.

I A-.-port.2 8 is'formed' inthe valve :sleeve 14 in the formof atransverse cut extending nearly to thetaxisoi the sleeve l 4, and of awidth preferably size of the aperture or throttle opening will increasein proportion to the square of the distance moved by the valve elementl2. Specifically, the area of throttle .openingincreases in accordancewith the formula for a parabola x =ay where m is a unitofdistance'through which the valve element 12 is moved orturned, y ithegarea of throttle opening, andv a is a constantiactor determined bythe dimensions of the valve and the units chosen for x and .y'. Forsimplicity of illustration, the factor a.is taken as'unity in the graphFig. 22. s i

The manner-in which the valve opensis illustrated in graph form iniFig.22. Inthis figure, the values of :r and 11/ have been arbitrarilychosen. In the graph, the-r coordinate represents arbitrary units of.the angle of valve opening.. The-y coordinate represents arbitraryunitsdash diagonally extending line B is the graph of a valve such as theordinary needle .valvewhich opens in accordance with a straight linelaw, and is introduced solely for purposes of comparison. Fig. 22demonstrates the advantage achieved by the improvedvalve disclosed whichopens in accordance with the parabolic law. From the graph,it willreadily be seen that the initial-increments of movement of the valvefromclosed position to open; will efiect a relatively small. increase inaperture and consequent table speed, whereas, as the valve continues itsmovement to open, increments ofrmovementof equal extent will producemuch larger increases of aperture particularly adapted for adjustment ofthe valve inthe'high'speed range. v

Forucontro-lling the movement of the-valve member l2, there is providedan enlarged valve stem-34 which passes through an oversize apere ture 35:in the wall 20 ofrthe machine frame, thence through an oversize'a'perture .38 inlanother .wall portion 48 of the machine frameand isformed with a screw --.thread 42 threaded through-a nut t4 secured-tothe outer face of the wall 40. At its outer endpthe valve stem, 34; hasi mountedthereon a manually operable, control knob 46' which is securedin position on the stembya set screw 48. -As shown insthe.;draw. ings,the nutv is formed with a circular outer edge having an annularfiange 50against which mounted toextend outwardly from the face. of the clampingring 52 projects into-an annular groove 60 formed in the under face ofthe manual controlknob 46 torpositively limit angular movement of thecontrol knob and valve stem 34 therewith in either direction. I

Inorder to insure the accurate positioning of thevalve member 12 axiallyof the valve sleeve Ilirrespective of any looseness or wear which mayexist between the. screw 42 and nut 44 elements, a helical take-upspring 64 isv coiled about the valve stem 34. between a washer 66retained onthe valve stem 34, and a sleeve abutment 68 arranged to bearagainst. the left hand or outer face fv the wall of the casing. Withthis construction it is appreciated that an axial jogging of the controlknob 46 and valve stem'34 against. the pressure of the spring 64 willhave the-effect of momentarily changing the speed .of the: drivensupport. It is appreciated further that such an accidentaljogging whichmight tend to increase the feed rate would involve aserious hazard ofoverloading and-damage both to the machine and, to the work beingoperated upon. With the illustratedconstruction, the thrust of. thespring upon the valve stem 34 and control knob 46 is outward to open forthe adjusted potary and harmless slowing of the driven support.In-ord-er to avoid any possible tendency ofthe take-up spring 64 or-itsassociated abutments 68 to become frictionally engaged against the wall20, with. the result that torsional strains may beset up in the spring64 tending to move the. valve stem 34 and associated parts rotation allyfrom adjusted position, the sleeve abutment 66 is keyed to turn with andto slide with relation toth valve stem 34 by means of a key 10 Y passingthrough a slot in the valve stem.

As illustrated, for example, in Figs. 1 and 2 of the drawings, thecontrol knob 46 is formed to provide an indicator dialill havingcalibrated markings thereon to. cooperate with a relativelystationary'marker 12 carried on the nut clampingiifring- 52. With the.illustrated construction, the dial H is calibrated in terms of inchesper minute ofv travel of a hydraulically-actuated grinding machine worksupporting table. These calibrations includea group of very slow tablespeeds'from 1 to 6 inches per minue, and a group of. more rapidlyincreasing higher speeds ranging from 16 to 144 inches per minute. V V

. The manner in which the ports 28 and are moved with relation to oneanother to cause the throttle opening to be increased in proportion to:thesquare of the increment of movementz of the. valve stem will bereadily. understood from an inspection of Figs. 4 to 6 showing thevalve. respectively in its fully opened, partly opened and fully closedpositions taken in connection with.

the diagrammatic developed. views of the parts. in the correspondingpositions of Figs. 7, 8 and 9. Starting with the fully closed positionof. Fig. 6,

itwill be seen that the valve member I2. is turned 7 5 so that theprojecting semi-cylindrical end portion of the valve member designatedat I4 is turned to fully blank off the-sleeve port 28 while at the sametime the valve member has been moved inwardly, or to the right from'theposition shown in Fig. 1, into its'sleeve M to such an extent. that thetransverse edge surface I6 of the semi-cylindrical cutout has movedbeyond the adjacent transverse edgesurfaoe 1B of the in-'- let port 28,so that the valve is entirely shut off. If the control knob 46 is nowrotated in a counterclockwise direction, the combined rotational andaxial movement thus imparted to'the valve member 12 causes the adjacentcorners of. the two ports 28 and30 to movediagonally into overlappingrelation withirelation to one another. Th -rotational orutransver'semovement of the valve member I 2 causes the two adj acent. verticaledges of the respective portsv to overlap, whereas the longitudinalcomponent .of' valve movement causes thecooperating transverse edges 16and 18 to overlap to produce the rectangular opening of Fig. 8, thisopening being thereafter in.-

creased by continued. rotational movement ofzthe The valvemechanismabove described has the advantage that it can be adjusted tooperatepwith a highdegree of precision, particularly over theslowspeedirange of adjustment,.while'at the-same time the .valve partsare. of simple construction and are inexpensively produced without anynecessityfor maintaining a high standard of precision in manufacture. .Afeature of the inven-e tion which contributes in large. measure td-the'highlya'ccurate results obtained, consists in the means foradjustmentemployed. in'connection with'the' setting up of the valvemechanism; so that the exact point of blanking off of the throttleaperture is readily determined, and-an accurate scale of speedadjustments maybe obtained particularly over the slow speed range of.the' valve.

The combination of the cooperating. rectangular valve ports and thescrew-threaded'bonnection for controlling therelative movement o f thevalve and valve sleeve-elements has been fou'n'dfof advantage in that itautomatically provides for-a slow rate of increase of valve aperture for'the initial increments of relative movement from closed to openposition of the valve, and thus per-'- mits the'use of substantialincrements of movement to produce the very fine speed changes requiredat the. low speeds of support movement. In this connection also, theprovision of the takeup spring 64 is of particular value toinsure theelimination of backlash in the screw thread and the consequentmaintenance of a' high degree of accuracy in the critical. axial settingof the valve element. M t, A preferred and advantageousmethodfor erfecting the adjustment of the valve mechanism is illustrated and willbedescribe'd in connection with Figs. 10 to 21 inclusive of thedrawings; as best shown in Figs. 10 and 11, for purposes of ad justmentthe hand knob 46 has been removed; a pin wrench ,84has been applied tothe adjustable nut 44', and an adjusting dog 86 having a split clampingportion and clamping screw this secured to the valve stem 34 in place ofthe man-- ual control. knob 46. The dog is'provid'ed at its outer endwith a pointer 90 havingaa wedge- 'in Figs; 13 and 18.

For convenience in (setting up the valve mechanism, a transverse screwdriver slot 94 is formed in, the end of'the, valve, stem exactlyparallel to the face of the semi-cylindrical cutout 30 formedinthe-yalve member 12. A'punch mark. 96 is formed in the end of thevalve stem 34 at one side of the ,slot 94 and in the same relationthereto as :the semi-cylindrical segmentFM-left by the cutout 30 at theend of the .valve member 12..

The: several steps of the operationof adjusting the valve mechanism arebriefly as follows: The adjusting dog 86 is mounted on the valve stem34with the pointer 90 in position vertically above the valve, stem 34,and with the punch mark 96 also in line with the pointer 90 as shown,for'example, in Figs. 10, 11 and 17. The screws 54 on the nut clampingcollar 52 are backed 01f just enough to permit the nut 44 to bev turnedwith the pin wrench 84. With. the hydraulic pressure on the system, thecontrol support which may be assumed to be a grinding machine worksupporting table, will either move indicating that the valve member I2is retracted out of thev-alve sleeve l4 so far as to uncover the inletport 28,

orthe table will be stopped, showing that the semi-cylindrical segment14' is projected sufiiciently into the sleeve M to blank off the port128. In either event, the nut 45 is rotated while the valve stem is heldstationary in the position of Fig. 10. Assuming that the nut is providedwith a right hand thread, a clockwiserotationzof 1 the nut will tend toopen, and a counterclockwise step in the operation of adjustment is,while leaving the nut stationary, to rotate the valve stem by means ofthe dog 86 in a counterclockwise direction until the table starts. Theblank: ing oiT point thus arrived at is the position shown The blankingoff point as show in Fig. 18, is marked with a'pencil on the surface of,the clamping ring 52 in alignment with the pointer 90 of the. dog. As athird step in the operation, the valve stem 34 is rotatedcounterclockwise to the position shown in Figs. 14 and 19, that is, withthe dog pointer directly beneath the valve stem, the nut 44 being heldstationary. For this position of the parts, the valve is wide openandthe table ismoved at a maximum speed governed by pump capacity. Asa'fourth step in the operation, while holding the valve stemsta tionary,the nut 44 is turned counterclockwise un til the table just stops. Thisis theposition' shown in Figs. 15 and of the drawings. It will be notedthat Figs. 13 and 18 show one preliminary blanking off position in whichthe cooperating longitudinal edges of the ports 28fand are about tooverlap as the result of the rotational movement of the valve member12,.while Figsr15 and 20 show another preliminary blanking oil positionin which the adjacent transyersefedges of the ports 28 and 30 are aboutto 'movelinto overlapping position as the result "of relative axialmovement of the valve'rnemberjlland'valve sleeve'l. V p

,From the position shown in Figs, 15 a nd 2 0 the valve stem and nutwill now be rotatedin unison in a clockwise direction until the pointeron the dog 86 lines up with the pencil mark on the surface of theclamping ring 52. 'In orderto 8 assist'in this operation, the link 92 ismoved on top of the handleof the pin wrench 84 and the two parts areheld together by finger pressure during. the rotational movement totheposition,

ofFigsi 16 and 21. The valve mechanism is now in the position ofadjustment. The clamping screwsxful are tightened to cause the clampingrin 52 to rigidly securethe nut 44 in adjusted position, and th dog 86is removed and replaced with the dialcontrol knob 46 which is now set sothat the speeds indicatedthereon check with the table speeds- Thesetting of the dial knob is accomplished by holding theknob against itsslow speed stop while-turning the valve stem, using a screw driverfitted into the screw driverslot 94 for this purpose until the desiredslow speedis reached. The locking "set screw 48 is now tightened,completing the operation.

It' has been found that the series of opera! tions above described arecapable of securing a very accurate adjustment of the valve mechanism,forthe reason that each of the blanking off positions is arrived atseparately, so that in each instance the aperture resultingfrom' theoverlapping of adjacent edges of the ports 28 and 30 is the product ofthe very small dimension in the direction of overlapping and of a relatively large transverse dimension, so that the efiective openingincreases from zero very rapidly' It will be understood that theinvention is not limited to the specific embodiment shown,.-and thatvarious deviations may be made therefrom without departing from thespirit and scope of theiappended claims; '15

What is claimed is: l i

1. A hydraulic control valve which comprises a cylindrical valve elementand a cylindrically chambered valve receiving element, said valveelement and chambered valve receiving element having cooperating valveports formed with rectilinear transverse and longitudinal edges substanti'ally square with the axis of" said cylindrical elementsandarranged' to be brought into overlapping'r'elation by'movement of thevalve element to provide a throttle, opening, a nut, an ex tension ofthevalve element threaded to the ma;

said valve and chambered valve receiving elements' being disposed withrelation to one another so that the screw movement of the valve elementrelative to the nut effects a substantially simultaneous Loyerlapping ofthe cooperating transverse and cooperating longitudinal edges of saidports to increase, the area of thethrottle opening of said valve fromclosed to open posi'-' tion, and means supporting the nut in fixed Iaxial relation to the valve receiving element and for rotatableadjustment with relation thereto, whereby rotation of the screw from afully closed position of the valve will indicate the adjusted angularposition of the threaded extension with relation to said supportingmeans for the blank-' ing-off of said longitudinal edges, and arotationaladjustment of the nut relativeto the threaded extensionwillindicate the adjusted position of the threaded extension axially withrelation t'o' the nut -for the blanking-offof said transverse edgesrand'a subsequent rotational movement of thenut and threaded extension asa unit toLthe previously'adjusted angular position of the threadedextension will accurately determine the 'shut-ofi position of the Valve.

52. A hydraulic-control valve-which comprises a cylindrical valveelementand a cylindrically chambered valve receiving; element, saidvalve elementsiand' arranged to'be brought into over-' lappingrelation'by movement ofthe valve element to provide athrottle opening,'awnut', an-

extension'of the valve element threaded-to the nut, said valve andchambered valve receiving elements "being disposed-with relation to oneanother'so that the screw-'movement of the valve element relativeto-thenut efiects a substantially simultaneous overlapping of the cooperating"transverse and cooperating longitudinal edges-of said ports-to increasethe area of thejthrottleopening of, said valve from closed to openposition, means supporting the nut in fixed*axial-re-- lationto thevalve receiving element and for rotational adjustment with relation tosaid threaded extension for adjustment of the rotational and axialposition-of the threated extension to effect said simultaneousoverlapping of said transverse and longitudinal edges, and spring meansconnected to bias the valve element axially against the nut and therebyto eliminate backlash in the threaded connection with the nut comprising:a coil spring coiled about and secured to the valve extension, and asleeve thrust element engaged by said coil spring keyed to slide uponand turn with said sleeve extension.

3. A hydraulic control valve which comprises a cylindrical valve elementand a cylindrically chambered valve receiving element, said valveelement and chambered valve receiving element having cooperating valveports formed with rectilinear transverse and longitudinal edgessubstantially square with the axis of said cylindrical elements andarranged to be brought into overlapping relation by movement of thevalve element to provide a throttle opening, a nut, an extension of thevalve element threaded to the nut, said valve element being disposedwith relation to the chambered valve receiving element so that a screwmovement of the valve element outwardly relative to the nut effectsoverlapping of the cooperating transverse and cooperating longitudinaledges of said ports to increase the area of the throttle opening of saidvalve from closed to open position, means supporting the nut in fixedaxial relation to the valve receiving element and for rotationaladjustment with relation to said threaded extension for adjustment ofthe rotational and axial position of said threaded extension to effectsaid simultaneous overlapping of said transverse and longitudinal edges,9, manual control disposed at the outer end of said valve extension, andspring means connected to bias said valve element axially outwardlyagainst the nut.

nut in a fixed axial relation to the valve receiving element and forrotational adjustment relative thereto, an extension of the valveelement threaded to the nut, said valve and chambered valve receivingelements being disposed with relation to one another so that the screwmovement tudinal edges, an indicator dial arranged for re tativeadjustment on said valve extension to1accord witha relative angularblank-off position of said valve elements'and a rel-atively'fixedindicator cooperating with said dial.

5. A hydraulic control valve which comprises;

a cylindrical valve element and a cylindrically chambered valvereceiving element, said valve element and chambered valve'receivingelement" having cooperating valve ports formed with'rec tilineartransverse and longitudinal edgesi'substantially square with-the axis ofsaidcylindrical elements, a nut. threaded to the valve element, meansfor supporting the nut in a rotatably adjustable .axially fixed relationto the valvelreceiveing element for independent adjustment ofiitheLvaxial and rotational position. of the threaded; valve element-forblanking-off of said respective. transverse and longitudinal .edges toeffectr'a 1' simultaneous overlapping of said transverse andlongitudinal edges, at adjacent corners of said ports moving from aclosed to an open position, :a dial supporting manual controller securedto said valve element for adjustment angularly to accord with therotationally adjusted blank-of]? position of the valve element, and astop device acting against said manual controller to limit therotational movement thereof.

6. A hydraulic control valve which comprises cylindrical valve and valvesleeve elements, said valve element having a semi-cylindrical cut-outformed at the inner end thereof to provide a port having rectilineartransverse and rectilinear longitudinal edges substantially square withthe axis of said valve elements, said valve sleeve having formed thereina transverse slot of a length axially of the valve sleeve element lessthan the length of the cut-out in the valve element and of a depthextending nearly to the axis of the sleeve element to provide a sideport having rectanuglar transverse and longitudinal edges, a nutthreaded to one of said elements, a support on which the nut is fixedaxially with relation to the other of said elements and for rotationaladjustment with relation thereto for effecting an independentdetermination of the relative rotational and axial blanking-01fpositions of said valve elements to efiect a simultaneous overlapping ofsaid transverse and longitudinal edges for a throttled opening of thevalve, and means for securing the nut to the support in an adjustedposition.

7. A hydraulic control valve which comprises a cylindrical valve elementand a cylindrically chambered valve receiving element, said valveelement and chambered valve receiving element having cooperating valveports formed with rectilinear transverse and longitudinal edgessubstantially square with the axis of said. valve elements and arrangedto have adjacent corners thereof brought into overlapping relation bymovement of the valve element to provide a throttle, a nut having athreaded connection with one of said cylindrical valve elements, asupport on which the nut is fixed axially with relation to the othertional adjustment with relation thereto for effect.

ing an independent determination of the relative rotational and axialblank-off positions of said valve elements, means on said supportmarking theangular-blank-ofi position of the movable cylindrical valveelement, means securing the nut to saidsupport for a position in whichthe mov-. able sleeve element is in said marked'rotational position andin which the nut and movable cylindrical valve element are in saiddetermined axial blank-01f position, and a dial supporting manualcontroller rotatably adjustable on said movable valve' element to accordwith the adjusted positions of said nut and threaded sleeve valveelement.

8. A hydraulic control valve which comprises cylindrical valve andvalve; sleeve elements, said valve element having a semi-cylindricalcut-out formed at the inner end thereof to provide a port havingrectilinear transverse and rectilinear longitudinal edges substantiallysquare with the axis of said valve elements, said valve sleeve havingformed therein a transverse slotof a length axially of the valve sleeveelement less than the length of the cut-out in the valve element and ofa depth extending nearly to the axis of the sleeve element to provide aside port having rectilinear transverse and longitudinal edges, a nut, a

threaded. extension of said valve element threaded to the nut, saidvalve and sleeve elements being disposed with relation to one another sothat I a screw movement of the vlave element outwardly relative to thenut effects a substantially simultaneous overlapping atadjacent cornersof the cooperating transverse and longitudinal edges of; said portstoopen the valve, means including a ring clamp supportingthe nut in fixedaxial re- I lation to the valve receiving element and for rotationaladjustment with relation thereto to determine the relative angular andrelative axial blank-off positions of said valve elements, and a dialsupporting manual controller angularly ad justable on said .valveextension in accordance with the angularly adjusted blank-01f positionof said valve extension. I

' v HANS C. WEIMAR.

REFERENCES CITED The following references are of record in the file' ofthis patent: f

UNITED STATES PATENTS

